Vinylindenes and some heteroanalogues in the Diels-Alder reaction. V. 3-Vinylindoles and quinones

Abstract

3-Vinylindoles give adducts containing a benzo- or naphtho-carbazole ring system by 1,4-cycloadditionsto 1,4-benzoquinone and 1,4- naphthoquinone respectively. The adducts are readily dehydrogenated to the corresponding heterocyclic quinones. No skeletal rearrangement accompanies oxidation with oxygen in base.